The present invention relates to a solar radiation collector of the type composed of a mat formed of a black foil member and a radiation pervious foil member, the two members being joined together along the outer edges of the mat and at interior locations of the mat to form an extended flow path and an inlet and outlet for a fluid heat carrier medium, the collector further including a cover connected to the mat along opposed edges thereof and arranged to be disposed in the path of solar radiation toward the mat with an air space being defined between the mat and the cover.
Solar radiation collectors of this type are disclosed in U.S. Pat. No. 4,059,095 wherein a further foil which is pervious to solar radiation, is disposed in front of the mat, when seen in the direction of the solar radiation, to serve as a cover, and is likewise welded, or heat sealed to the mat along the lines where the two foils forming the mat are connected, the cover being connected in such a manner that air-filled chambers are formed, between these connecting lines, between the mat on the one hand and the cover on the other hand. These air-filled chambers serve as heat insulation.